Cluster headache is always unilateral, or one-sided. However, some people may experience some variability of the side on which their headache occurs.
Most people with cluster headaches describe their pain as occurring around or behind the eye. Pain may radiate along the forehead, into the jaw or along the gum line and into the teeth, or across the cheek of the affected side. Infrequently, pain may extend into the ear, neck, or shoulder.
In addition to head pain, many people with cluster headaches have symptoms and signs that may include:
Watering of the eye (tearing)
Eyelid drooping or swelling
Runny nose (rhinorrhea)
People with cluster headaches also may have symptoms that are more commonly associated migraine headaches, including sensitivity to light, sounds, or odors may occur. However, unlike migraine headache, movement does not worsen the pain of a cluster headache. In fact, many people describe a sense of restlessness during their pain.
The headaches associated with cluster occur in groups. While the headaches themselves may be brief (as short as 15 minutes), the headaches can recur up to eight times in 24 hours.
Headaches may last as long as 3 hours. Cluster cycles may last for only a single day, or may linger for many weeks.